This invention relates to a method and apparatus for mounting components and more particularly to an improved method and apparatus for determining the amount of correction that should be made to compensate for the way in which the component is picked up.
A wide variety of apparatus have been proposed for picking up small components such as IC's resistors, condensers or the like and positioning them for mounting on a substrate such as a printed circuit board or the like. In order to permit accurate mounting of the component, the orientation of the component relative to the pick up device once it is picked up must be determined. Normally the components are presented to the pick up device at a station and frequently the components are mounted in recesses on a tape or the like. As such, it is not accurately known what the position of the component is relative to the pick up device when the component is picked up.
Thus, considering the "X", "Y" axes and the rotational position .theta. about the axis of the pick up device, it is necessary to measure the correction factors both in the "X" direction, in the "Y" direction and the rotational position of the component relative to the pick up when the component is picked up. Various measuring devices have been proposed for this purpose.
The disadvantage of necessitating separate measurements is that the measurements all take time and, therefore, the previously proposed devices have been relatively slow in operation.
It is, therefore, a principal object to this invention to provide an improved method and apparatus for determining the correction necessary for a component that is picked up by a gripping device so that it can be accurately positioned.
It is a further object to this invention to provide an improved method and apparatus for determining the position of a component that is picked up by a pick up device.